The Zombies Infected Tower Defense buy and upgrade towers to defend yourself from the various waves of big and small zombies, and play to view all the details on how to survive your first wave of many zombies, and then click the tower you want to choose and place it anywhere on the map which is show on top, but before you do that make sure you have the right amount of gold to purchase the multiple towers so click the tower that you have just placed on the right map and click upgrade to all the stats on the gun to make it stronger and then shoot further, and fire faster as well to make a better result.